(1) Field of the Invention
The present disclosure belongs to the technical field of ultrasound image processing methods. In particular, the present disclosure relates to an ultrasound image processing method that quantifies a degree of rheumatoid arthritis, and to an ultrasound diagnostic apparatus that uses the aforementioned method.
(2) Description of the Related Art
Ultrasound diagnostic apparatuses have conventionally been used to examine body parts such as the heart or abdomen, or to examine a fetus. In recent years, as a consequence of improved ultrasound diagnostic apparatus analytical ability, it has also become possible to use an ultrasound diagnostic apparatus to examine body parts close to the surface of the body. Therefore, an ultrasound diagnostic apparatus may be used in the field of orthopedics in order to examine body parts such as bones, tendons, and muscles, or may be used to evaluate inflammation of a joint in diagnosis of rheumatoid arthritis.
Evaluation of rheumatic inflammation is performed using a B-mode image and a Doppler mode image (for example, Takao KOIKE; The New Concept of Rheumatoid Arthritis Care -Ultrasonography for Joints-; Medikaru-Rebyu-Sha; p 40-43; Mar. 10, 2014). More specifically, the B-mode image is used to examine thickness of an articular cavity, presence of bone erosion, and build-up of synovial fluid, whereas the Doppler mode image is used to examine presence of angiogenesis.
In clinical research there is much interest in methods for quantifying a degree of inflammation. For example, previously proposed methods include a semi-quantitative method of subjectively categorizing inflammation into four stages, a BOX method of counting Doppler signals in a rectangular area, and a trace method of counting Doppler signals in a triangular area of which bones form two sides. Disease quantification such as described above is useful in determining the effectiveness of treatment.